The invention concerns an antenna for portable devices such as the radio receiver of a radio timepiece, as described in detail in European Pat. No. 0 242 717.
In the case of small timepieces, such as, for example, small fashion watches or travel alarm clocks, it is difficult to locate a long-wave antenna of adequate capacity to receive the time information transmitted by radio, in the small, angled space available between the clock movement and the inner wall of the case or hinged structural parts.
The development of a radio timepiece in the form of a wristwatch has heretofore been considered not feasible, firstly, because of the insufficient space required for the placement of the radio receive (see R. Bermbach and M. Lobjinski, "Novel Radio Timepieces From the Data Technology Institute" in FUNKUHREN, edited by W. Hilberg, center page 170), wherein the problems of the location of an adequate magnetic core frame antenna volume is not even considered. The problem of the space requirements of the receiver has been solved in the meantime, because now fixedly tuned long-wave receivers integrated on a chip are available for radio timepieces, see for example, German Pat. No. 35 16 810. However, there remains the problem of miniaturizing adequately powerful passive antennas for long-wave receivers, which, for example in the case of modern consumer timepieces, are to be operated with a single cell battery.
In view of the above, it is an object of the invention to develop an antenna which may be installed even under narrow and angled spacial conditions and can be used as a high capacity long-wave antenna for portable devices, such as a radio wristwatch.